Firing mechanism for automatic rifles



March 19, 1957 M. JOURDAT FIRING MECHANISM FOR AUTQMATIC vPalmas FiledApril 11. 1952 2 Sheets-Sheet 1 mms hvcof vla/m JAHormey-b?? March 19,1957 M.'JouRDA1' 2,785,605

FIRING MECHANISM FOR AUTOMATIC RIFLES Filed April 11, 1952 2Sheets-smeet 2 jssos inmNG MECHANI'SM Fon AUTOMATIC RiFLEs Marc Jourdat,St.-Etienne,Y France, assignor to Societe a responsablite limiteeGevarm, Saint-Etienne (Loire), France, a French corporation ApplicationApril 11, 19527, Serial No. 281,746 Claims priority, application FranceApril 17, 1951 3 Claims. (Cl. 89-140) t Automatic ries asproducedhitherto include an intri- "cate mechanism, the parts of which areditiicult to machine and are consequently expensive.

The automatic rifle forming the object of my invention has for itsobject to remove these drawbacks and comprises a bolt chamber to thefront of which is screwed the gun barrel and wherein the actual rie boltis slidably litted and urged forwardly by a spring while the boltcarries at its front a rod-shaped extension adapted to strike thecartridge in the barrel, said rod-shaped extension being slidinglyfitted inside an extension of reduced diameter of the bolt chamber whilethere is pivotally secured to a carrier member or receiver rigid withthe bolt chamber a tumbler adapted to release the rie bolt out of its`rear inoperative position when said tumbler is released by the trigger.

Y Accompanying drawings illustrate by way of example a preferredembodiment of my invention. In said drawings:

Fig. l is a longitudinal cross-section of the rie illustrated in itscocked position before firing.

Fig. 2 is a cross-section thereof through line II--II of Fig. 1.

Fig. 3 is a longitudinal cross-section of the rifle shown at the momentof the automatic positioning of the cartridge just before tiring.

Fig. 4 is a partial cross-sectional view of the cocking means for therille bolt before the latter recoils or kicks.

Fig. 5 illustrates in longitudinal cross-sectional view the rie at themoment of the recoil of the rie bolt and of the automatic ejection ofthe empty cartridge case.

Fig. 6 is a cross-section through line VI-VI of Fig. 5.

Fig. 7 is an outer plan view corresponding to Fig. 5.

Fig. 8 shows the cocking device for the rifle bolt in the case of thetiring of a burst.

Fig. 9 is a perspective view ofthe rocking spindle controllingselectively the tiring of a burst or of separate shots.

, to slide in said b olt chamber and is arrested in its forward movementby the shoulder between the two elementary chambers. The bolt.3 includesa cylindrical body 31 that is slidingly itted inside the large diameterchamber 2 and Y a front extensionassuming the shape of a cylindrical rod32 acts asa piston inside the front chamber 21 the inner diameter ofwhich corresponds to the diameter of the bead of the cartridge. The bolt3 carries a cocking lever K 4 (Fig. 7) that projects outwardly of thechamber 2,

while it is longitudinally guided inside a slot 23 of the latter.

The forward stroke of the bolt 3 is obtained by means of the coil spring5 that is wound round the shouldered .United States Patent O i 2,785,605PatentedfMar. y19,1957

rod 6 engaging an axial bore provided in the bolt and in Vor charger 8designed in the conventional manner may enter it, said charger beingsecured through a rocking bracket 9 pivotallyv carried by aparallelopipedic carrier or receiver 10 extending underneath the boltchamber.

The carrier 10 is rigidly secured to the chamber! by means of a screw 11or any other suitable means. This carrier includes at its rear end atrigger guard 12 and it is recessed at 101 in order Yto house theautomatic cocking device.

This automatic cocking device includes a trigger 13 that is submitted tothe vertical thrust of a coil spring 131. VThis trigger 13 is housedinside the carrier 10 and it is pivotally secured over a transversepivot pin 14 enlsaid pivot pin engaging a vertically elongated port 152`in said trigger plate.

The sear 15 is provided in its lower portion with a further elongatedport 153 through which passes an angularly shiftable spindle or pivotpin 17 through which it is possible to produce the firing either as aburst or as a series of separate shots. The sear 15 is also subjected tothe action of a coil spring 18 engaging a stud 19 on the carrier 10 andadapted to urge the sear forwardly and to the action of a compressedcoil 20 urging the sear upwardly into its cocked position.

In order to cock the rie, the bolt is urged rearwardly either by handthrough actuation of the cocking lever 4 or automatically as describedhereinafter, until the shoulder 33 on the bolt is engaged by the upperend of the scar 15. The latter that forms a stop, that is capable ofreceding, rocks with reference to the pivot pin 16 under the action ofthe torque generated by the spring 5 urging the bolt forwardly until thefront surface of the elongated opening 153 in the rocking sear abutsagainst the at side of the oblong spindle 17 as illustrated by the arrowA of Fig. 1.

When tiring (see Fig. 3) and upon depression of the trigger 13 in thedirection of the arrow B of Fig. 3 the 50 sear 15 rocks as shown by thearrow C and it revolves round the pivot pin 16 until the front shoulder33 of the bolt is'released by said scar. However, the trigger 13 isprovided on its upper surface with an adjustable screw 22 that abutsjust before the release of the bolt 3 against the lower surface of thebolt chamber 2 whereby, after contact of said lower surface with thescrew 22, a continued depression of the trigger 13 produces a furtherangular shifting thereof by reason of the clearance of the pivot pin 14with reference to the port 132.

This further shifting of the trigger is felt by the hunter using therie, by reason of the different values of the engages thechamber 11 .ofthe gun barrel 1 until the .bead ofthe .cartridge .is in contact withthe` rear en d of the barrel 1. At this moment, the sudden stopping ofthe cartridge X provides the desired percusslon by .reason of.theinertiadeveloped by the high speed movement of the bolt. The rod3?,isprovided at its end with a .projecting nose 34V .that strikes the.cartridge along Vits annular surface.

After the firing, the pressure of the explosion gases urges rearwardlythe bolt A3 while `the cartridge case is extracted and ejectedautomatically. s

To this end and as shown in Fig. 5, the bolt 3 as it moves rearwardlyuncovers the flaring lateral opening 25 in the bolt chamber 2. The emptycase urged rearwardly `together with the bolt 3 escapes then suddenlythrough thelsaid opening 25, is blownoutwardly and ejected.

AWhen the iringis atan end (Fig-4) the sear A15 is urged by th-e coilsprings 18l and 20, into Va pivotingrmotion with reference to thepivotpin 1,6 in the direction of the arrow D. During this pivotal movement,the nose 15l of the sear releases the nose 133 of the trigger 13 wherebysaid trigger and sear no longer engage each other. The sear 15 is thusurgedvertically'by the springs 18 and 20' which allows a furtherVautomatic cooking of the rifle after the recoil of the bolt 3 to therear of the Sear. The trigger 13 which` lis now released by theautomatic cocking device isv returnedto its tiringposition by the spring131. The movement of the sear 15 which any rocking of the latter. Inthis position, theactuation of the trigger 13 only provides for thevertical shifting of the Sear 15 as shown by the direction of the arrowsE and consequently this produces a burst firing, as no .pre-

liminary action on the trigger is then required.

The automatic rifle according tomy invention is of an extremely simpleexecution by reason of thesimple nature of its different parts most ofwhich may beobtaiued by turning from the bar orthe like standardmechanical operations.

On the other hand, this rifle includes none fof the standard membersknown and used hitherto .such asthe extractor, the ejector, ythe movablestriker, theslope feedi ing the barrel and the like.

What Inclaim is:

1. inan automatic rifle, in combination: a bolt chamber; a bolt slidableinrsaid chamber; a main spring in said chamber and urging said boltforward; a receiver rigid with said chamber; a Sear memberin saidreceiver-normally engagingthe boltagainst the action of said spring; insaid sear member, a first velongated* slot substantially orthogonal tothe bolt; la first pivot pin rigidwith said receiver, said first slot.engagingsaid pivot pin and being adapted to slide on said pivot pin indirections substantially orthogonal to the bolt; a trigger in saidreceiver, adapted to engage yieldingly said sear member and movable withrespect to saidsear member; in said trigger, a second elongated slotsubstantially orthogonal to-the bolt; a second pivot pin rigid with saidreceiver and engaging said second slot, whereby said trigger is adaptedto slide over said second pivot pin in directions substantiallyorthogonal Ato the bolt; said trigger being held directly by said searmember when theY latter engages the bolt against the action of the mainspring; said trigger being adapted, upon depression, to release, saidsear member from -engagement with they bolt; at least one spring meansVbetween said receiver and said sear member and adapted to urge ,saidscar member against the V`bolt upon recoil thereof, and to control theoperative and inoperative positions of said sear member relative to thebolt, the bolt chamber and the trigger; said bolt, during its forwardand recoil directions of rnotion,-` urging said sear member outside saidbolt chamber until said bolt has returned to lits rearward inoperativeposition, at which said one spring means urges said sear member inlocking engagement with .said bolt, and at which said trigger has beenreleased from engagement with said sear member and lreturned. to itsinoperative position.

2. InA an automatic rifle, thecombination as claimed in claim 1,comprising further: elastic means between the bottom-wall of saidreceiver andthe lower face of said trigger, forward of said second pivotpin and adapted to urge said trigger upwards over said second pivot pin;an adjustable screw projecting from the upper face of Vsaidtriggerrearwards of ysaid second slot, and adapted lto abut against `thelower surface .of said bolt chamber upon rocking of said trigger aroundsaid secondpivot pin during the early stage of depression of saidtrigger priorg to the release ofthe bolt; the duration of said earlystage being controlled bythe height of the projection Vof said screw outof said lupper face; whereby, during a continued depression of s aidVtrigger beyond ysaidiearlystage, said screw causes the forward endofsaid .trigger to vpivot around said .Second pivot pin against theationof .said elastic means, therebyausing said trigger .to actuate saidsear member to release said bolt and lin- `dicatping Ato the user theprecise timing of boltrelease and striking in relation to theearlyvstage and continued A depressions respectively of said trigger.

3. ln an automatic rie, the r,cornbination as claimed i .inclaim l,comprising furtherzfinsaiddsear member, a

'thirzd elongated slot disposed below, 4and substantially coaxial with,said first slot, and substantially orthogonal ,tosaidvboln a rotary.spindle supported by the Walls 0f said receiver and passing throughsaid.l third s1ot; said third slotl having a transverse widthsubstantiallygreater than that of said rst slot; said spindle having two4fiat .parallel sidewalls forming an intermediate portion 1ocated withinthe walls of said .receiver and adaptedu to cooperate with said thirdslot; the width ofjsaidintermediate portion being substantially equal tothe transverse width of said third slot; hand operated means connectedto said spindle and adapted .to shift said .spindle into a yfirstposition for which theat side wallsofrsaid intermediate portion aresubstantially .orthogonal to said gbolt, thereby/allowing shiftingandbiasing of said sear `member around said first pivot pin, and into yasecond .alternative position for which said fiatv side .walls of saidintermediate portion `extend transversely acrosssaid third slot andengage the side walls of said .third slot to allow only a verticalshifting ofv .said sear member, whereby said automatic rifle may beoperated for burst .firing when said spindle is in said second positionand .for controlled firing when `said spindle is insaid .first position.

References YCited in the file .of this patent vUi`U'lfl-D STATES PATENTSGreat Britain Oct. 6, Y1937

